Order of HT leads?

Order of HT leads?

Author
Discussion

pbrettle

Original Poster:

3,280 posts

283 months

Saturday 9th August 2003
quotequote all
Ok, so the misfire that I have been suffering has got a little (well actually lot) worse. So, replaced the spark plugs and managed to scrape almost every knuckle in the process. Anyway, I did each spark plug in order and was careful replacing each HT lead and shield correctly - I think!

However, I just wanted to check one thing. On the drivers side bank of cylinders each HT lead is in order - they make a nice order of four. On the passenger side they are not quite so ordered - the middle two are swapped over. Now this probably doesnt make sense as they are plugged into the distributor which is circular anyway! So, what I was wondering was, what is the order of the HT leads and how do you tell which one should be connected to which spark plug / cylinder?

I have the Bible and I failed to find anything in there. Hints and tips welcome.

Incidentally the misfire is pretty much constant now and VERY noticable below 3000 revs. You can hear the off-beat of one cylinder not firing correctly. But it does seem to be smoothish which probably indicates that it is consistent at least. I have HT leads on order at the moment, but welcome to any hints and tips to correct this - I am at a miss to think what could be causing the fault. My understanding is that it is usually the HT leads or spark plugs.....Oh, and checked the distributor which looks OK too - but without disconnecting each HT lead I cant really check (hence the question on what the order is).

Cheers,

Paul

RCA

1,769 posts

268 months

Saturday 9th August 2003
quotequote all
Hang On, will check now!!

Mark.S

473 posts

277 months

Saturday 9th August 2003
quotequote all
Had a misfire sorted by Mark Adams on my first trip to power engineering. Turned out to be one of the plug extender/shield thingymajigs had degenerated and was causing an arc.

RCA

1,769 posts

268 months

Saturday 9th August 2003
quotequote all
Right not sure now to explain this!!

Starting on the passenger side at the front where the oil cap is, No. 1, then accross to the other side at front No. 2, then back accross and up one No. 3 etc

Will try and add diagram as this is probably not making any sense!!!

RCA

1,769 posts

268 months

Saturday 9th August 2003
quotequote all


pbrettle

Original Poster:

3,280 posts

283 months

Saturday 9th August 2003
quotequote all
cheers guys - thats excellent.... I'll have a look in a minute. The sun has reached round to my car on the drive now and its hot to the touch.... ooch....

Heath24

70 posts

249 months

Saturday 9th August 2003
quotequote all
My Chimaera has been suffering from an intermittant fault/misfire. The engine loses power and then cuts out. It can be re-started after a few sec's, and runs normally for a period of time.
It currently is back with the garage where I bought it, they have run diagnostic test's on it electrically, and fuel injection etc, everything seems to check out OK.
The only thing they have been able to find is that the HT leads seem to be a little on the low side, and have suggested replacement to which I have agreed, because they did seem hard and brittle.
Are these similar symptons to yours?? I would like to have my car back, especially this weather as I am now begining to feel a little as I haven't had a drive for nearly 2 weeks now.

pbrettle

Original Poster:

3,280 posts

283 months

Saturday 9th August 2003
quotequote all
Right, sorted out now. I have checked the layout for the HT leads and they match, thanks RCA.

However, when running through each lead to cylinder I found that cylinder 5's lead came off in my hand.... strange cos it seemed fine earlier today when I had them all off. Anyway, its broken and fused and this will explain the misfire.... so nice and simple and all I need is a set of HT leads...

Good to know that it isnt anything major and my original thoughts were correct. Thanks chaps and cant wait until the leads come now...

Cheers,

Paul

pbrettle

Original Poster:

3,280 posts

283 months

Saturday 9th August 2003
quotequote all
Heath24 said:
My Chimaera has been suffering from an intermittant fault/misfire. The engine loses power and then cuts out. It can be re-started after a few sec's, and runs normally for a period of time.
It currently is back with the garage where I bought it, they have run diagnostic test's on it electrically, and fuel injection etc, everything seems to check out OK.
The only thing they have been able to find is that the HT leads seem to be a little on the low side, and have suggested replacement to which I have agreed, because they did seem hard and brittle.
Are these similar symptons to yours?? I would like to have my car back, especially this weather as I am now begining to feel a little as I haven't had a drive for nearly 2 weeks now.


HT Leads (and to a small degree the sparks) are susceptible to heat damage. The engine gets hot and they break down - eventually breaking. Where an ordinary car you can expect to get 40K miles out of a set, with a TVR you are lucky to get full performance for more than half of that. Aftermarket ones last longer, but the benefits are debateable.

I would have thought that something like the HT leads might be causing the problems. It might be simple and thus sending the ECU funny - hence the cut out. But chances are that this is something more important like an ECU sensor (though this need not be expensive). Check it checked out by a TVR / Rover engine specialist and they will probably find the fault quickly (I am assuming that you bought it from a non-TVR specialist thats all). The Rover engines are really clever but basically simple. If all else fails I would suggest a run with Mark Adams - he will find and issolate the fault quickly.... he's worth every penny...

Heath24

70 posts

249 months

Sunday 10th August 2003
quotequote all
pbrettle said:

Heath24 said:
My Chimaera has been suffering from an intermittant fault/misfire. The engine loses power and then cuts out. It can be re-started after a few sec's, and runs normally for a period of time.
It currently is back with the garage where I bought it, they have run diagnostic test's on it electrically, and fuel injection etc, everything seems to check out OK.
The only thing they have been able to find is that the HT leads seem to be a little on the low side, and have suggested replacement to which I have agreed, because they did seem hard and brittle.
Are these similar symptons to yours?? I would like to have my car back, especially this weather as I am now begining to feel a little as I haven't had a drive for nearly 2 weeks now.



HT Leads (and to a small degree the sparks) are susceptible to heat damage. The engine gets hot and they break down - eventually breaking. Where an ordinary car you can expect to get 40K miles out of a set, with a TVR you are lucky to get full performance for more than half of that. Aftermarket ones last longer, but the benefits are debateable.

I would have thought that something like the HT leads might be causing the problems. It might be simple and thus sending the ECU funny - hence the cut out. But chances are that this is something more important like an ECU sensor (though this need not be expensive). Check it checked out by a TVR / Rover engine specialist and they will probably find the fault quickly (I am assuming that you bought it from a non-TVR specialist thats all). The Rover engines are really clever but basically simple. If all else fails I would suggest a run with Mark Adams - he will find and issolate the fault quickly.... he's worth every penny...


Thanks for the advice. Yes did buy from a non-TVR dealer, but they are being helpful put it back to them as its still under warranty, will pass on the comments, if I don't get any joy next step will be a specialist.
Cheers

Paul

shpub

8,507 posts

272 months

Monday 11th August 2003
quotequote all
pbrettle said:


I have the Bible and I failed to find anything in there. Hints and tips welcome.



Page 67

shpub

8,507 posts

272 months

Monday 11th August 2003
quotequote all
pbrettle said:


I have the Bible and I failed to find anything in there. Hints and tips welcome.



Page 67... In the chapter on ignition system...